Accepts single or multiple option IDs to assign to product. (multiple IDs would be &option_id=xxxxxxxxx repeated for each ID to assign, where xxxxxxxxx represents each ID value to assign.) Optional.

category_id

Accepts single or multiple category IDs to assign product to. (multiple IDs would be &category_id=xxxxxxxxx repeated for each ID to assign, where xxxxxxxxx represents each ID value to assign.) Optional.